Method of repairing a wind turbine blade

ABSTRACT

A method of repairing a wind turbine blade while mounted on a tower without removing the blade from the tower is provided. The method may begin by positioning the wind turbine blade in a substantially vertical orientation. Next, a containment structure is suspended from a nacelle via a hoisting system that positions the containment structure at a damaged portion of the blade. The damaged portion is enclosed within the containment structure and the temperature of the air within the containment structure is controlled. The blade is repaired by removing a damaged portion of the blade, and installing a repair portion to the blade where the damaged portion was removed. The method may conclude by operating the hoisting system to remove the containment structure from the blade.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/684,378, filed on Jan. 8, 2010, all of which is incorporated byreference as if completely written herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not applicable.

TECHNICAL FIELD

The present disclosure relates to wind turbines, and more particularlyto a method of repairing a wind turbine blade while mounted on a towerwithout removing the blade from the tower.

BACKGROUND OF THE INVENTION

Wind turbines are becoming increasingly popular as a means forgenerating “green” energy. As with other means for generating energy, itis desirable for wind turbines to produce energy with as high a level ofefficiency as possible. One of the main things that can significantlylower wind turbine efficiency is damage to a wind turbine blade, andmore specifically, damage to the aerodynamic profile of the blade. Thus,in order to operate the wind turbine more efficiently and to preventfurther damage, the damaged blade should be repaired in a timely manner.

Depending on the amount of damage and the location of the damage, ablade may be repaired while it is still attached to the tower. Forexample, small nicks and cracks in the shell of a blade may typically berepaired without having to remove the blade from the tower. However,when the damage affects the aerodynamic profile of the blade, or thedamage is located on, or near, the structural backbone of the blade,generally referred to as a spar cap, then the blade is typically removedfrom the tower and repairs are performed on the ground. The primaryreason for removing the blade is so that the blade can be repaired in anenvironment where the blade is not under any stresses or loads to ensurethat the aerodynamic profile of the blade is maintained and notpermanently compromised.

What is needed in the art is a method of repairing any type of damage toa wind turbine blade while the blade is mounted on a tower withoutremoving the blade from the tower. The claimed method and the variousapparatus associated with performing the method is intended to meet thisneed.

SUMMARY OF INVENTION

In its most general configuration, the disclosed method of repairing awind turbine blade advances the state of the art with a variety of newcapabilities and overcomes many of the shortcomings of prior methods innew and novel ways. In its most general sense, the disclosed methodovercomes the shortcomings and limitations of the prior art in any of anumber of generally effective configurations. The various apparatusassociated with the method demonstrate such capabilities and overcomesmany of the shortcomings of prior devices in new and novel ways.

The disclosure is directed to a method of repairing a wind turbine bladewhile mounted on a tower without removing the blade from the tower. Inone embodiment, the first step of the method includes positioning theblade in a substantially vertical orientation. The second step includessecuring a blade reinforcement structure to the blade to reduce stresson a portion of the blade. Next, a damaged portion of the blade isremoved, and a repair portion is installed to the blade where thedamaged portion was removed. After the repairs have been made, themethod concludes by removing the blade reinforcement structure from theblade.

In one particular embodiment, the step of securing a blade reinforcementstructure to the blade further includes the step of securing a clampingstructure to the blade. The step of securing a clamping structureincludes securing a primary proximal clamp above a max chord locationand securing a primary distal clamp below the max chord location, andfurther includes the step of interlocking the primary proximal clamp andthe primary distal clamp with a clamp interlock structure. The clampinterlock structure may be utilized to apply a force to the primaryproximal clamp and the primary distal clamp to reduce stress on aportion of the blade.

In another embodiment, the step of securing the blade reinforcementstructure to the blade further includes the step of stabilizing theblade from the tower by securing a load transfer structure to the bladeand the tower. The load transfer structure may include an adjustableblade-to-tower support having a blade attachment device, alongitudinally adjustable device, and a tower attachment device. Theload transfer structure may be used to apply a force to the blade.

In yet another embodiment, the method further includes the step ofsuspending the blade reinforcement structure from a nacelle via ahoisting system. The hoisting system may include a sinistral cable, adextral cable, a sinistral hoist, and a dextral hoist. Moreover, themethod further includes the step of operating the sinistral hoist andthe dextral hoist to raise or lower the blade reinforcement structure tothe damaged portion of the blade.

These variations, modifications, alternatives, and alterations of thevarious preferred embodiments may be used alone or in combination withone another, as will become more readily apparent to those with skill inthe art with reference to the following detailed description of thepreferred embodiments and the accompanying figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Without limiting the scope of the method as claimed below and referringnow to the drawings and figures:

FIG. 1 is a side elevation view of a wind turbine blade, not to scale;

FIG. 2 is a cross-sectional view of the wind turbine blade taken alongsection line 2-2 of FIG. 1, not to scale;

FIG. 3 shows an embodiment of a blade reinforcement structure secured tothe wind turbine blade, not to scale;

FIG. 4 shows an embodiment of a blade reinforcement structure having areinforcement structure work platform secured to the wind turbine blade,not to scale;

FIG. 5 shows an embodiment of a blade reinforcement structure secured tothe wind turbine blade, not to scale;

FIG. 6 shows an embodiment of a blade reinforcement structure and anembodiment of a containment structure secured to the wind turbine blade,not to scale;

FIG. 7 shows an embodiment of a blade reinforcement structure secured tothe wind turbine blade, not to scale;

FIG. 8 shows an embodiment of a blade reinforcement structure secured tothe wind turbine blade, not to scale;

FIG. 9 is a cross-sectional view of the wind turbine blade taken alongsection line 9-9 of FIG. 7, not to scale;

FIG. 10 shows an embodiment of a blade reinforcement structure securedto the wind turbine blade and suspended by a hoisting system, not toscale;

FIG. 11 shows an embodiment of a blade reinforcement structure securedto the wind turbine blade, not to scale;

FIG. 12 shows an embodiment of a blade reinforcement structure securedto the wind turbine blade, not to scale;

FIG. 13 shows an embodiment of a blade reinforcement structure securedto the wind turbine blade, not to scale;

FIG. 14 shows an embodiment of a blade reinforcement structure securedto the wind turbine blade, not to scale;

FIG. 15 shows an embodiment of a blade reinforcement structure securedto the wind turbine blade, not to scale;

FIG. 16 shows a cross-sectional view of the wind turbine blade takenalong section line 16-16 of FIG. 15, not to scale;

FIG. 17 shows a cross-sectional view of a wind turbine blade with anembodiment of a clamping structure secured thereto, not to scale; and

FIG. 18 shows an embodiment of a blade reinforcement structure securedto the wind turbine blade, not to scale.

These drawings are provided to assist in the understanding of theexemplary embodiments of the various apparatus associated with themethod as described in more detail below and should not be construed asunduly limiting the claimed method. In particular, the relative spacing,positioning, sizing and dimensions of the various elements illustratedin the drawings are not drawn to scale and may have been exaggerated,reduced or otherwise modified for the purpose of improved clarity. Thoseof ordinary skill in the art will also appreciate that a range ofalternative configurations have been omitted simply to improve theclarity and reduce the number of drawings.

DETAILED DESCRIPTION OF THE INVENTION

The claimed method of repairing a wind turbine blade (100) enables asignificant advance in the state of the art. The preferred embodimentsof the apparatus associated with the method accomplish this by new andnovel arrangements of elements that are configured in unique and novelways and which demonstrate previously unavailable but preferred anddesirable capabilities. The detailed description set forth below inconnection with the drawings is intended merely as a description of thepresently preferred embodiments of the method, and is not intended torepresent the only form in which the method may be performed orimplemented. The description sets forth the designs, functions, means,and apparatus for implementing the method in connection with theillustrated embodiments. It is to be understood, however, that the sameor equivalent functions and features may be accomplished by differentembodiments that are also intended to be encompassed within the spiritand scope of the claimed method.

With reference now to FIGS. 1 and 2, a conventional wind turbine forconverting the kinetic energy of the wind into electrical energy isillustrated. Perhaps the most important components of a conventionalwind turbine are the blades (100), which will be described in moredetail below. The blades (100), of which there are typically three, areattached to a hub (300) that is connected to a nacelle (400). Thenacelle (400) houses a drive train comprising connecting shafts, agearbox, support bearings, a generator, and control equipment, alongwith other machinery. A tower (500), typically constructed of steel, iserected on a foundation and supports the nacelle (400), hub (300), andblades (100).

Still referring to FIGS. 1 and 2, the various portions and components ofa typical wind turbine blade (100) will now be described. As seen inFIG. 1, the blade (100) has a root (110), which is joined to the hub(300), and a tip (120). The blade (100) also includes a leading edge(130), a trailing edge (140), and a leading-to-trailing edge axis (150),which may defined as an imaginary line extending between the forwardmostpoint of the leading edge (130) and the rearwardmost point of thetrailing edge (140), as seen in FIG. 2. To help generate lift, the blade(100) has an aerodynamic profile with a suction side (160) and apressure side (170). As seen in FIG. 1, the blade (100) has a max chordlocation (180) that corresponds to the widest portion of the blade(100), which defines the max chord distance (190), as seen in FIG. 2.

Generally, the blade (100) comprises a shell (200) that is typicallyformed of a glass fiber reinforced composite. The shell (200) may begenerally hollow or contain a core material, such as balsa wood or PVCfoam; however, those with skill in the art will recognize that othermaterials may be used to form the shell (200). In order to provide theblade (100) with increased structural reinforcement, the shell (200)typically includes a spar cap (210) and a shear web (220). As seen inFIG. 2, the blade (100) may have a primary suction side spar cap (212)connected to a primary pressure side spar cap (216) by a primary shearweb (220). Similarly, the blade (100) may have a secondary suction sidespar cap (214) connected to a secondary pressure side spar cap (218) bya secondary shear web (224). Spar caps (210) have typically beenconstructed from glass fiber reinforced composites; however, spar caps(210) made of stronger materials, such as carbon fiber reinforcedcomposites and other advanced materials, are also available.

Referring again to FIGS. 1 and 2, it can be seen that the blade (100)has a damaged portion (230). The damaged portion (230) may result from anumber of causes, such as a lightning strike, a bird strike, or fatigue,just to name a few. A wind turbine operating with damaged blades (100)will inevitably decrease the wind turbine's operating efficiency. Thus,when a damaged portion (230) is discovered on a blade (100) it isimperative to repair the blade (100) in order to prevent further damageand to improve the wind turbine's efficiency.

As opposed to prior methods for repairing a wind turbine blade (100),the presently disclosed method of repairing a wind turbine blade (100)does not require removing the blade (100) from the tower (500). In oneembodiment, the first step of the method includes positioning the blade(100) in a substantially vertical orientation. The second step includessecuring a blade reinforcement structure (600) to the blade (100) toreduce stress on a portion of the blade (100). Next, a damaged portion(230) of the blade (100) is removed. Further, a repair portion (240) isinstalled to the blade (100) where the damaged portion (230) wasremoved. And finally, the blade reinforcement structure (600) is removedfrom the blade (100). Now, the steps of the method, as well asembodiments of the apparatus for carrying out the method, will bedescribed in greater detail.

As previously mentioned, the method begins by positioning a blade (100)that is to be repaired in a substantially vertical orientation. What ismeant by a substantially vertical orientation is that the root (110) andthe tip (120) of the blade (100) point directly toward the ground alongan imaginary vertical plane. A typical wind turbine will have controlequipment that allows an operator to position the blade (100) byrotating the blade (100) to the desired orientation and then locking theblade (100) in that orientation. In addition, the wind turbine may alsoinclude control equipment that allows an operator to adjust the pitch ofthe blade (100) to position the blade (100) so that theleading-to-trailing edge axis (150) has a particular orientation to awind direction. In a particular embodiment, the method may furtherinclude the step of positioning the blade (100) so that theleading-to-trailing edge axis (150) is substantially parallel to a winddirection. Such positioning can help reduce stresses on the suction side(160) and pressure side (170) of the blade (100) caused by the wind whenmaking repairs.

When repairing a portion of a blade (100) it is important to reduce thestress at the point of the repair as much as possible. Obviously, if theblade (100) is bending due to wind loads then portions of the shell(200) will have compressive stress and portions will have tensilestress. If the portion of the blade (100) being repaired is under highstress while the repairs are made, then any such repairs will bestructurally compromised and subject to early failure. Moreover, makingrepairs to a portion of the blade (100) that is under considerablestress substantially increases the risk that the blade (100) profilewill be compromised, which can substantially lower the operatingefficiency of the wind turbine or cause blade failure. This becomes evenmore important when the damaged portion (230) includes at least aportion of a spar cap (210) of the blade (100), which is the primarystructural support for the blade (100). Currently, when the damagedportion (230) includes a portion of a spar cap (210), the blade (100) isremoved from the hub (300) to carry out repairs to ensure that theprofile of the blade (100) is not altered.

As such, an additional step in an embodiment of the method includessecuring a blade reinforcement structure (600) to the blade (100) toreduce stress on a portion of the blade (100). In one particularembodiment, the blade reinforcement structure (600) may include aclamping structure (700) having a primary proximal clamp (800) connectedto a primary distal clamp (1000) by a clamp interlock structure (1200),as seen in FIG. 3. Thus, the step of securing a blade reinforcementstructure (600) to the blade (100) may further include the step ofsecuring the clamping structure (700) to the blade (100), which mayinclude the step of securing the primary proximal clamp (800) above amax chord location (180) and securing a primary distal clamp (1000)below the max chord location (180). However, one with skill in the artwill recognize that the primary proximal clamp (800) and the primarydistal clamp (1000) may be successfully secured along any portion of theblade (100). The step of securing a blade reinforcement structure (600)to the blade (100) may further include the step of interlocking theprimary proximal clamp (800) and the primary distal clamp (1000) with aclamp interlock structure (1200). Additionally, the primary proximalclamp (800) and the primary distal clamp (1000) may be positioned suchthat the damaged portion (230) of the blade (100) to be repaired islocated between the primary proximal clamp (800) and the primary distalclamp (1000) to help reinforce and reduce stresses on the damagedportion (230) of the blade (100).

As one with skill in the art will appreciate, the clamping structure(700), including the primary proximal clamp (800) and the primary distalclamp (1000), should be configured to closely follow the contour of theblade (100) to ensure a secure fit. As such, the clamping structure(700) may include molded portions so that the clamping structure (700)conforms to the particular contours of the blade (100). Alternatively,the clamping structure (700) may comprise straps that may be cinched toapply a clamping force to the blade (100). The straps may containprojecting contact surfaces to account for the contour of the blade(100). Moreover, the clamping structure (700), including the primaryproximal clamp (800) and the primary distal clamp (1000), may comprise aframe type structure for surrounding the blade (100) that includesbiased reinforcements that apply a force on the blade (100). Forexample, and as seen in FIG. 17, the clamping structure (700) mayinclude at least one inflatable bladder (750). In this embodiment, whenthe clamping structure (700) is in the desired position, the inflatablebladder (750) is filled with air to provide a clamping effect on theblade (100). Generally, the inflatable bladder (750) comprises a durablefabric material, such as Kevlar, nylon or polyurethane, that covers aninflatable rubber core so that the inflatable bladder (750) is capableof conforming to the general contour of the blade (100).

In still another embodiment, the clamping structure (700), including theprimary proximal clamp (800) and the primary distal clamp (1000), maycomprise reinforced vacuum blankets, as seen in FIG. 18. The reinforcedvacuum blanket type clamps (800, 1000) may generally comprise a flexibleand durable material, such as Kevlar. As seen in FIG. 18, reinforcedvacuum blanket type clamps (800, 1000) are configured to completelyencircle the blade (100) and may be joined to one another via a clampinterlock structure (1200). To that end, the reinforced vacuum blankettype clamps (800, 1000) may be configured as tubes or as planar sheetsof material that are joined at their ends. A number of reinforcementdevices (810, 1010) may be fixedly attached to the material. Thereinforcement devices (810, 1010) may be structural devices that aregenerally longer than they are wide and may be comprised of metal orhigh strength plastic. In this particular embodiment, the clamping forceis applied by connecting the reinforced vacuum blanket type clamps (800,1000) to a vacuum source, which creates a vacuum such that the clamps(800, 1000) are drawn into contact with the blade (100). The reinforcedvacuum blanket type clamps (800, 1000) may be configured such that avacuum is created to evacuate the air from the void between the materialand the blade (100), thereby drawing the material and the reinforcementdevices (810, 1010) into intimate contact with the blade (100), or thevacuum may draw the reinforcement devices (810, 1010) into contact withthe blade (100), with the material following by default. Adjacentreinforcement devices (810, 1010) may be connected to each other by onlythe material, or they may be more rigidly attached to one another whilestill accommodating movement between them to facilitate use on the widearray of blade sizes and profiles. The reinforced vacuum blanket typeclamps (800, 1000) preferably include an attachment nozzle to facilitateconnection to a vacuum source.

One with skill in the art will also appreciate that the clampingstructure (700) should be sized and configured in such a way that theclamping force and other loads exerted on the clamping structure (700)are distributed evenly and across a large enough area of the blade (100)so that the chances of damaging the blade (100) are minimized.

With reference to FIGS. 3 and 4, and as mentioned above, the primaryproximal clamp (800) and the primary distal clamp (1000) are interlockedto one another with a clamp interlock structure (1200). The clampinterlock structure (1200) may be a single structure or include multiplestructures such as a compressive side interlock structure (1202), atensile side interlock structure (1204), or both, as explained below.

In one particular embodiment, the clamp interlock structure (1200)includes at least a compressive side interlock structure (1202), and themethod further includes the step of applying force to the primaryproximal clamp (800) and the primary distal clamp (1000) with thecompressive side interlock structure (1202), thereby reducing stress ona portion of the blade (100) located between the primary proximal clamp(800) and the primary distal clamp (1000). As seen in FIG. 4, thecompressive side interlock structure (1202) is positioned near where theblade (100) is experiencing compressive forces caused by the wind, whichin this particular case happens to be on the trailing edge (140) side ofthe blade (100). The compressive side interlock structure (1202) isconfigured to exert force on the primary proximal and primary distalclamps (800, 1000) at a particular location on the clamps (800, 1000) tocounteract the compressive forces to reduce the stress on the blade(100), as noted by the force arrows in FIG. 4. As one skilled in the artwill appreciate, the compressive side interlock structure (1202) mayapply force to the primary proximal and primary distal clamps (800,1000) by utilizing, for example, a mechanical actuator, a hydraulicactuator, or a pneumatic actuator, just to name a few.

In another embodiment, the clamp interlock structure (1200)alternatively includes at least a tensile side interlock structure(1204), and the method further includes the step of applying force tothe primary proximal clamp (800) and the primary distal clamp (1000)with the tensile side interlock structure (1204), thereby reducingstress on a portion of the blade (100) located between the primaryproximal clamp (800) and the primary distal clamp (1000). As seen inFIG. 4, the tensile side interlock structure (1204) is positioned nearwhere the blade (100) is experiencing tensile forces caused by the wind,which in this particular case happens to be the leading edge (130) sideof the blade (100). The tensile side interlock structure (1204) isconfigured to exert force on the primary proximal and primary distalclamps (800, 1000) to counteract the tensile forces to reduce the stresson the blade (100), as noted by the force arrows in FIG. 4. As oneskilled in the art will appreciate, the tensile side interlock structure(1204) may apply force to the primary proximal and primary distal clamps(800, 1000) by utilizing, for example, a mechanical actuator, ahydraulic actuator, or a pneumatic actuator, just to name a few.

In yet another embodiment, the clamp interlock structure (1200) includesat least a compressive side interlock structure (1202) and a tensileside interlock structure (1204), and the method further includes thestep of applying force to the primary proximal and primary distal clamps(800, 1000) with the compressive side interlock structure (1202) and thetensile side interlock structure (1204), thereby reducing stress on aportion of the blade (100) located between the primary proximal andprimary distal clamps (800, 1000). As seen in FIG. 4, and as mentionedabove, the compressive side interlock structure (1202) is positionednear where the blade (100) is experiencing compressive forces caused bythe wind, which in this particular case happens to be the trailing edge(140) side of the blade (100), and the tensile side interlock structure(1204) is positioned near where the blade (100) is experiencing tensileforces caused by the wind, which in this particular case happens to bethe leading edge (130) side of the blade (100). In this particularembodiment, the compressive and tensile side interlock structures (1202,1204) apply force to the primary proximal and primary distal clamps(800, 1000) to counteract the compressive forces and the tensile forces,respectively, to help reduce the stress on the blade (100), as noted bythe force arrows in FIG. 4. As previously mentioned, one skilled in theart will appreciate that the compressive and tensile side interlockstructures (1202, 1204) may utilize, by way of example only and notlimitation, a mechanical actuator, a hydraulic actuator, or a pneumaticactuator to apply force to the primary proximal and primary distalclamps (800, 1000).

Referring now to FIG. 5, an additional embodiment of the bladereinforcement structure (600) is shown. In this particular embodiment,the blade reinforcement structure (600) further includes a secondaryproximal clamp (900) secured to the blade (100) above the primaryproximal clamp (800) and a secondary distal clamp (1100) secured to theblade (100) below the primary distal clamp (1000). As seen in FIG. 5,the primary proximal clamp (800) and the secondary proximal clamp (900)are interlocked to one another with a secondary proximal clamp interlockstructure (1210), while the primary distal clamp (1000) and thesecondary distal clamp (1100) are interlocked to one another with asecondary distal clamp interlock structure (1220).

The secondary proximal and distal clamps (900, 1100) are preferablysized and configured in accordance with the principles corresponding tothe primary proximal and distal clamps (800, 1000), as previouslydiscussed. Moreover, the secondary proximal and distal clamp interlockstructures (1210, 1220) are preferably designed and capable offunctioning in the same manner is as the embodiments of the clampinterlock structure (1200) discussed above. Thus, the step of securing ablade reinforcement structure (600) to the blade (100) may furtherinclude the steps of securing a secondary proximal clamp (900) above theprimary proximal clamp (800) and securing a secondary distal clamp(1100) below the primary distal clamp (1000). In addition, the step ofsecuring a blade reinforcement structure (600) to the blade (100) mayfurther include the steps of interlocking the primary proximal clamp(800) and the secondary proximal clamp (900) with a secondary proximalclamp interlock structure (1210) and interlocking the primary distalclamp (1000) and the secondary distal clamp (1100) with a secondarydistal clamp interlock structure (1220).

With reference now to FIGS. 4-6, in one embodiment, the bladereinforcement structure (600) may include a reinforcement structure workplatform (610). As seen in FIGS. 4-6, the reinforcement structure workplatform (610) is secured to the blade reinforcement structure (600) atthe primary distal clamp (1000); however, one with skill in the art willrecognize that the reinforcement structure work platform (610) may besecured to any portion of the blade reinforcement structure (600). Thus,the step of securing a blade reinforcement structure (600) to the blade(100) may further include the step of securing a reinforcement workplatform (610) to the blade reinforcement structure (600). Thereinforcement structure work platform (610) provides a surface fromwhich a worker may access the blade (100) and make repairs to a damagedportion (230) of the blade (100). The reinforcement structure workplatform (610) may partially surround the blade (100), as seen in FIGS.4-6, or may totally surround the blade (100). Preferably, thereinforcement structure work platform (610) includes a railing toprovide fall protection.

As previously mentioned, the primary proximal clamp (800) may be securedabove the max chord location (180), as seen in FIG. 3. In a particularembodiment, the primary proximal clamp (800) is configured such that thesecured primary proximal clamp (800) cannot pass the max chord location(180). For example, the primary proximal clamp (800) may have a widththat is less than the max chord distance (190). Such an embodimentensures that the clamping structure (700) will not slide off the blade(100) should the primary proximal clamp (800) disengage the blade (100).

The blade reinforcement structure (600) may be lifted by a crane andmanually secured to the blade (100) by workers suspended from the hub(300) or nacelle (400). Alternatively, and now referring to FIG. 10, theblade reinforcement structure (600) may be suspended from the nacelle(400), or alternatively the hub (300), by a hoisting system (1600). Thehoisting system (1600) may include a sinistral cable (1610), a dextralcable (1620), a sinistral hoist (1630), and a dextral hoist (1640). Thesinistral and dextral hoists (1630, 1640) may be drum hoists mounted tothe nacelle (400) or the hub (300), or traction hoists mounted to theblade reinforcement structure (600) that are capable of ascending anddescending along the sinistral and dextral cables (1610, 1620), as seenin FIG. 10. As with all conventional hoists, the sinistral and dextralhoists (1630, 1640) include controls to allow a user to operate thesinistral and dextral hoists (1630, 1640) to raise or lower the bladereinforcement structure (600) to a desired portion of the blade (100).Thus, in one particular embodiment of the method, the step of securingthe blade reinforcement structure (600) to the blade (100) may furtherinclude the step of suspending the blade reinforcement structure (600)from the nacelle (400) via a hoisting system (1600) including asinistral cable (1610), a dextral cable (1620), a sinistral hoist(1630), and a dextral hoist (1640), and further including the step ofoperating the sinistral hoist (1630) and the dextral hoist (1640) toraise or lower the blade reinforcement structure (600) to the damagedportion (230). After the blade reinforcement structure (600) is raisedor lowered to the desired position it may be secured to the blade (100).

With reference now to FIG. 13, an additional embodiment of the clampingstructure (700) is shown in which the primary proximal clamp (800) andthe primary distal clamp (1000) are positioned away from one another ina horizontal direction, rather than the previously disclosed verticalorientation. As seen in FIG. 13, the primary proximal clamp (800) andthe primary distal clamp (1000) are formed with a truss-like structure.As discussed above, the portions of the clamping structure (700) thatare in direct contact with the blade (100) may include molded portionsto conform to the particular contours of the blade (100). Moreover, andas one with skill in the art will appreciate, the clamping structure(700) should be sized and configured in such a way that the clampingforce and other loads exerted on the clamping structure (700) aredistributed evenly and across a large enough area of the blade (100) sothat the chances of damaging the blade (100) are minimized. As shown inFIG. 13, the primary proximal clamp (800) and the primary distal clamp(1000) are interlocked to one another with a clamp interlock structure(1200). The clamp interlock structure (1200) is configured to exertforce on the primary proximal and primary distal clamps (800, 1000) tocounteract forces acting on the blade (100) to reduce the stress on theblade (100). As one skilled in the art will appreciate, the clampinterlock structure (1200) may apply force to the primary proximal andprimary distal clamps (800, 1000) by utilizing, for example, amechanical actuator, a hydraulic actuator, or a pneumatic actuator, justto name a few.

Referring now to FIG. 14, another embodiment of the clamping structure(700) is illustrated. As seen in FIG. 14, the clamping structure (700)includes a primary proximal clamp (800), a primary distal clamp (1000),and a secondary distal clamp (1100). Similar to the previously discussedembodiment, the primary proximal clamp (800), the primary distal clamp(1000), and the secondary distal clamp (1100) are each formed with atruss-like structure. As previously discussed, the portions of theclamping structure (700) that are in direct contact with the blade (100)may include molded portions to conform to the particular contours of theblade (100) to ensure a secure fit. By utilizing a secondary distalclamp (1100), this particular embodiment of the clamping structure (700)helps to ensure that the clamping force and other loads exerted on theclamping structure (700) are distributed more evenly and across a largerarea of the blade (100) to reduce the chances of damaging the blade(100).

In this embodiment the orientation of the hub (300) and the position ofthe blades (100) are selected for ease of reducing the stress in thevicinity of the damaged portion (230). In this embodiment it is easierto apply stress reducing loads to the blade (100) on the suction side(160) and pressure side (170), rather than the leading edge (130) ortrailing edge (140). Thus, the pitch of the blade (100) is selecteddepending on the location of the damaged portion (230) so that stressreducing loads may be applied to the suction side (160) and pressureside (170) to achieve significant stress reduction in the vicinity ofthe damaged portion (230).

For example, in FIG. 13 the damaged portion (230) is located on thesuction side (160) or the pressure side (170) such that positioning thepitch of the blade (100) so the leading-to-trailing edge axis (150) isroughly perpendicular to the direction of the wind allows the primaryproximal clamp (800) and the primary distal clamp (1000) to bepositioned such that the clamp interlock structure (1200) can simplyreduce the stress in the vicinity of the damaged portion (230). In thisexample, the wind causes the blade (100) to bend such that the blade tip(120) deflects toward the tower (500). Thus, assuming the damagedportion (230) is somewhere near the illustrated position of where theclamp interlock structure (1200), primary proximal clamp (800) and theprimary distal clamp (1000) are positioned, and are in contact with theblade (100), the clamp interlock structure (1200) may draw the clamps(800, 1000) toward each other thereby reducing the bend of the blade(100) and thereby reducing the stress in the vicinity of the damagedportion (230).

One with skill in the art will appreciate that depending on the locationof the damaged portion (230) on the blade (100) in the leading edge(130) to trailing edge (140) direction, the pitch of the blade can beadjusted to reduce the stress in the vicinity of the damaged portion(230) when force is applied to the clamps (800, 1000) in a directionthat is largely orthogonal to the leading-to-trailing edge axis (150).Further, although the side elevation views of FIGS. 13 and 14 onlyillustrate one pair of “contacting feet” on each clamp (800, 1000),there may be multiple “contacting feet” positioned in the direction ofthe leading-to-trailing edge axis (150) to aid in distributing the loadapplied by the clamp interlock structure (1200) to focus where thedesired stress reduction is achieved while accounting for the complexshape of the blade (100).

Still referring to FIG. 14, it can be seen that the primary proximalclamp (800) is interlocked to both the primary distal clamp (1000) andthe secondary distal clamp (1100) with clamp interlock structures(1200). Each clamp interlock structure (1200) is configured to exertforce on the primary proximal clamp (800), primary distal clamp (1000),and the secondary distal clamp (1100) to counteract forces acting on theblade (100) to reduce the stress on the blade (100). As one skilled inthe art will appreciate, the clamp interlock structure (1200) may applyforce to the primary proximal clamp (800), primary distal clamp (1000),and the secondary distal clamp (1100) by utilizing, for example, amechanical actuator, a hydraulic actuator, or a pneumatic actuator, justto name a few.

In an alternative embodiment, the step of securing the bladereinforcement structure (600) to the blade (100) may further include thestep of stabilizing the blade (100) from the tower (500), as seen inFIGS. 7, 8, 11, 12 and 15. The step of stabilizing the blade (100) fromthe tower (500) serves to counteract forces on the blade (100) andreduce stress in the vicinity of a damaged portion (230). As previouslymentioned, making repairs to the damaged portion (230) of the blade(100) under stress may structurally compromise the repair portion (240),and moreover, may compromise the blade (100) profile, which cansubstantially lower the operating efficiency of the wind turbine.

In one particular embodiment seen in FIG. 7, the blade reinforcementstructure (600) comprises a load transfer structure (1300) including anadjustable blade-to-tower support (1400) having a blade attachmentdevice (1410), a longitudinally adjustable device (1420), and a towerattachment device (1430). Thus, the step of stabilizing the blade (100)from the tower (500) may be accomplished by securing a load transferstructure (1300) to the blade (100) and the tower (500). Moreover, thestep of stabilizing the blade (100) from the tower (500) may furtherinclude the step of applying a force to the blade (100) with the loadtransfer structure (1300). Preferably, the load transfer structure(1300) is secured to the blade (100) below the damaged portion (230).

The adjustable blade-to-tower support (1400) may be any device capableof applying a force towards the blade (100), towards the tower (500), ortowards both the blade (100) and tower (500). This force may be createdby the longitudinally adjustable device (1420), for example, byextending the blade attachment device (1410) towards the blade (100),extending the tower attachment device (1430) towards the tower (500), orboth. As such, the longitudinally adjustable device (1420) may be amechanical actuator, a hydraulic actuator, or a pneumatic actuator, justto name a few.

As one with skill in the art will appreciate, the blade attachmentdevice (1410) should be configured to closely follow the contour of theblade (100) to help distribute the load more evenly across a larger areaof the blade (100). Similarly, the tower attachment device (1430) shouldbe configured to closely follow the contour of the tower (500) to helpdistribute the load more evenly across a larger area of the tower (500).Thus, the blade attachment device (1410) may include a molded portion toconform to the particular contours of the blade (100), and the towerattachment device (1430) may include a molded portion to conform to theparticular contours of the tower (500).

With reference now to FIGS. 7 and 9, one will observe that the leadingedge (130) of the blade (100) has been rotated such that it is no longerdirectly facing the wind direction. As mentioned above, conventionalwind turbines typically include control equipment that allows anoperator to adjust the pitch of the blade (100) to position the blade(100) so that the leading-to-trailing edge axis (150) has a particularorientation to a wind direction. This is particularly advantageous whensecuring the load transfer structure (1300) to the blade (100) and thetower (500). The advantage lies in the fact that the blade attachmentdevice (1410) may be attached to the suction or pressure sides (160,170) of the blade (100) instead of the leading and trailing edges (130,140) of the blade (100). The suction and pressure sides (160, 170) ofthe blade (100) provide much more surface area, and thus the loads andstresses where the blade attachment device (1410) contacts the blade(100) are able to be distributed over a larger area of the blade (100),which minimizes the risk of damage to the blade (100). In a particularembodiment, the method may further include the step of positioning theblade (100) so that a leading-to-trailing edge axis (150) is at leasttwenty-five degrees from a wind direction. Moreover, the method mayfurther include the step of positioning the blade (100) so that aleading-to-trailing edge axis (150) is at least forty-five degrees froma wind direction. Even further, the method may further include the stepof positioning the blade (100) so that a leading-to-trailing edge axis(150) is at least seventy-five degrees from a wind direction, which asseen in FIG. 9 is about ninety-five degrees. In addition to providing alarger surface area of the blade (100) for the blade attachment device(1430) to contact, such positioning can reduce stresses on the blade(100) caused by the wind when making repairs.

Using a single adjustable blade-to-tower support (1400) may notsufficiently stabilize the blade (100) throughout the entire length ofthe blade (100), and thus the blade (100) may still be subject tostresses that could compromise any repairs made to the blade (100).Therefore, in another embodiment, the load transfer structure (1300) mayfurther include a secondary adjustable blade-to-tower support (1500)having a secondary blade attachment device (1510), a secondarylongitudinally adjustable device (1520), and a secondary towerattachment device (1530), as seen in FIG. 8. The secondary adjustableblade-to-tower support (1500) and its components may be constructedaccording to the principles discussed above with respect to theadjustable blade-to-tower support (1400) and its components. Byproviding a secondary adjustable blade-to-tower support (1500), theblade (100) may be stabilized such that the load on the blade (100) iscounteracted at two separate points to further reduce stress in thevicinity of the damaged portion (230). Preferably, when utilizing anadjustable blade-to-tower support (1400) and a secondary adjustableblade-to-tower support (1500), one adjustable blade-to-tower support(1400, 1500) is positioned above a damaged portion (230) of the blade(100) to be repaired, and the remaining adjustable blade-to-towersupport (1400, 1500) is positioned below the damaged portion (230). Thisensures that at least the damaged portion (230) of the blade (100) isstabilized when repairs are carried out. Further, one skilled in the artwill understand that it may be desirable for the supports (1400, 1500)to act in opposite directions. For instance, in the illustrated exampleof FIG. 8 the secondary adjustable blade-to-tower support (1500) may beforcing the deflected blade tip (120) away from the tower (500), whilethe adjustable blade-to-tower support (1400) is pulling a portion of theblade (100) toward the tower (500) to reduce stress in the vicinity ofthe damaged portion (230). Further, one with skill in the art willappreciate that the load transfer structure (1300) may include more thantwo adjustable blade-to-tower supports (1400, 1500) to further stabilizeand reinforce the blade (100) throughout the entire length.

With reference now to FIG. 11, in one particular embodiment, the bladeattachment device (1410) may include a primary proximal clamp (800) forapplying a clamping force to the blade (100). Similarly, for anembodiment having a secondary adjustable blade-to-tower support (1500),the secondary blade attachment device (1510) may include a primarydistal clamp (1000) for applying a clamping force to the blade (100).Additionally, and as seen in FIG. 11, the tower attachment device (1430)and the secondary tower attachment device (1530) may be formed asclamping devices that apply a clamping force to the tower (500) tosecure the adjustable blade-to-tower supports (1400, 1500) to the tower(500). As previously discussed, the primary proximal and primary distalclamps (800, 1000) should be configured to closely follow the contour ofthe blade (100) to ensure a secure fit. As such, the primary proximaland primary distal clamps (800, 1000) may include molded portions toconform to the particular contours of the blade (100). Still further,the blade attachment device (1410) and the secondary blade attachmentdevice (1510) may include reinforced vacuum blanket type clamps (800,1000), as described above and seen in FIG. 18. Moreover, one with skillin the art will appreciate that the primary proximal and primary distalclamps (800, 1000) should be sized and configured such that the clampingforces are distributed evenly and across a large enough area of theblade (100) so that the chances of damaging the blade (100) areminimized.

Referring now to FIG. 12, in another embodiment, the blade attachmentdevice (1410) may include a blade attachment vacuum device (1412) andthe tower attachment device (1430) may include a tower attachment vacuumdevice (1432). Similarly, for an embodiment having a secondaryadjustable blade-to-tower support (1500), the secondary blade attachmentdevice (1510) may include a secondary blade attachment vacuum device(1512) and the secondary tower attachment device (1530) may include asecondary tower attachment vacuum device (1532). The blade attachmentand tower attachment vacuum devices (1412, 1512, 1432, 1532) may be, byway of example only and not limitation, vacuum pads or vacuum cups thatare joined to a vacuum source or a compressed air source. For thereasons previously discussed with respect to the blade and towerattachment devices (1410, 1430), the blade and tower attachment vacuumdevices (1412, 1512, 1432, 1532) should likewise be configured toclosely follow the contours of the blade (100) and tower (500).

With reference now to FIGS. 15 and 16, in one embodiment, the bladeattachment device (1410) may comprise a U-shaped bracket member havingat least one blade attachment vacuum device (1412). This U-shapedbracket member embodiment allows the blade (100) to be oriented into thewind direction to minimize wind loads on the blade (100) during repair.Thus, the trailing edge (140) may be pointed toward the tower (500), andthe blade (100) reinforced from the tower (500), without applying a loaddirectly to the trailing edge (140). Preferably, the blade attachmentdevice (1410) includes at least two blade attachment vacuum devices(1412) so that the blade attachment device (1410) is capable ofattachment on the suction side (160) and pressure side (170).Furthermore, it is preferable for the blade attachment vacuum devices(1412) to be movable along the blade attachment device (1410) and to beextendable and retractable from the blade attachment device (1410). Aspreviously described, the blade attachment vacuum devices (1412) may be,by way of example only and not limitation, vacuum pads or vacuum cupsthat are joined to a vacuum source or a compressed air source. Moreover,the blade attachment vacuum devices (1412) should be capable of closelyfollowing the contour of the blade (100). For embodiments having asecondary adjustable blade-to-tower support (1500), the secondary bladeattachment device (1510) may be configured in the same manner as theblade attachment device (1400) just described.

In another embodiment, the adjustable blade-to-tower support (1400) mayinclude a hinged joint (1440) and the secondary adjustableblade-to-tower support (1500) may include a secondary hinged joint(1540), as seen in FIG. 12. The hinged joints (1440, 1540) may belocated adjacent the tower attachment devices (1430, 1530) so that theadjustable blade-to-tower supports (1400, 1500) are capable of pivotingtowards the blade (100). In fact, by providing the adjustableblade-to-tower supports (1400, 1500) with hinged joints (1440, 1450),the adjustable blade-to-tower supports (1400, 1500) may be attached tothe tower (500) and pivoted towards the blade (100) when the blade is tobe stabilized during repairs, or pivoted towards the tower (500) whenthe blade (100) is moving. In another embodiment the adjustableblade-to-tower supports (1400, 1500) are permanently attached to thetower (500) thereby eliminating the need to manually install theblade-to-tower supports (1400, 1500) every time a blade (100) isrepaired.

The blade (100) may be constructed with stress sensing devices, such asa strain gauge. The stress sensing devices may be arranged along thelength of the blade (100), for example, in or on the shell (200), or inor on a spar cap (210). Such stress sensing devices can provide anindication of the actual stresses on the blade (100) and the particularareas of the blade (100) that are under stress. By knowing the amount ofstress and the particular locations of stress along the blade (100), theblade reinforcement structure (600) may be adjusted to provide theproper amount of force to neutralize or reduce the stress on a portionof the blade (100). Adjustments to the blade reinforcement structure(600) may be accomplished manually by an operator, or by an automaticcontrol system that adjusts the amount of force exerted by the bladereinforcement structure (600) based on the stress sensed by the stresssensing devices.

After securing the blade reinforcement structure (600) to the blade(100) to reduce stress, the method continues by performing repairoperations on the blade (100). Generally, the repair operations includeremoving a damaged portion (230) of the blade (100), as illustrated inFIG. 2, which is followed by installing a repair portion (240) to theblade (100) where the damaged portion (230) was removed. The damagedportion (230) may be removed through conventional techniques such asgrinding, sanding, and cutting operations. For example, a damagedportion (230) of a blade (100) may comprise a delaminated area of theshell (200). To remove the damaged portion (230), the delaminated areamay be cut out or ground down to a depth corresponding to the deepestdamage. It should be noted that removal of the damaged portion (230)does not require removal of an entire portion of the blade (100),although such removal may be possible. After the damaged portion (230)is removed, a repair portion (240) may be installed. The repair portion(240) may be thought of as material that is intentionally added to theblade (100) to restore the blade's (100) physical state or mechanicalproperties. Installation of the repair portion (240) may compriseapplying multiple layers of an appropriate resin/hardener mixture andfiberglass plies to the removed damaged portion (230). Moreover,installation of the repair portion (240) may simply comprise filling theremoved damaged portion (230) with an appropriate filler compound, suchas an epoxy, a polyester, or a polyurethane, just to name a few.

One with skill in the art will appreciate that any conventional windturbine blade (100) repair technique or operation, such as scarf patchrepairs or plug and patch repairs to name a couple, may be utilized toremove a damaged portion (230) and install a repair portion (240).

In another embodiment, the method may further include the step ofenclosing the damaged portion (230) of the blade (100) within acontainment structure (620), as seen in FIG. 6. This step is preferablyperformed subsequent to securing the blade reinforcement structure (600)to the blade (100) and prior to performing any repair operations on theblade (100). The containment structure (620) allows the damaged portion(230) of the blade (100) to be shielded from the external environmentwhen repairs are made. Moreover, the containment structure (620)prevents contaminants and particulates created during the repair processfrom entering the external environment. The containment structure (620)should be configured to provide a tight seal around the blade (100),both above and below the damaged portion (230). Additionally, thecontainment structure (620) should be sized to allow at least one workerto easily access and make repairs to the blade (100). For example, thecontainment structure (620) may be about three meters tall and provide aspace extending at least two meters in all directions from the surfaceof the blade (100). As seen in FIG. 6, the containment structure (620)encloses the damaged portion (230) of the blade (100), as well as thereinforcement structure work platform (610). Preferably the containmentstructure (620) is constructed of a plastic material that is alsowaterproof, such as a polypropylene tarpaulin. Moreover, the containmentstructure (620) may include a frame to help support the plasticmaterial.

As mentioned above, the containment structure (620) is configured toshield workers from the external environment when carrying out repairs.Typically, it is considered unsafe in the industry to attempt bladerepairs when the wind speed is above 8 m/s. However, the presentcontainment structure (620) allows workers to safely perform blade workwhen wind speeds are above 8 m/s without the risk of losing balance dueto strong wind gusts. Additionally, the containment structure (620)shields the portion of the blade (100) being worked upon from the directeffects of the wind, which can reduce stresses on the portion of theblade (100) being repaired.

The containment structure (620) may be equipped with a number offeatures to facilitate repair work while avoiding exposure to externalconditions. For example, the containment structure (620) may includemultiple power outlets that are supplied with electrical power fromground or tower based generators to provide a power source for tools orlighting. The containment structure (620) may also include air linessupplied with air from ground or tower based air compressors. Further,the containment structure (620) may include its own lighting system toprovide workers with appropriate lighting to carry out repairs.

In yet another embodiment, the method may further include the step ofcontrolling the temperature of the air within the containment structure(620). This step may be accomplished by providing the containmentstructure (620) with access to an HVAC system, as seen in FIG. 6. Suchan embodiment provides the ability to perform necessary repair work inextreme high or extreme low temperatures, which might otherwise bepostponed until favorable conditions are achieved. Moreover, controllingthe air temperature within the containment structure (620) allows theworker to create a more pleasant working environment regardless of theexternal environment. In addition, many of the materials used to repairthe blade (100) may need to undergo a temperature controlled curingprocess. As such, the step of controlling the air temperature within thecontainment structure (620) allows the containment structure (620) to beheated or cooled so that the repair portion (240) of the blade mayproperly cure. Moreover, the method may further include the step ofcontrolling the humidity of the air within the containment structure(620). This step may also be accomplished by utilizing the HVAC system,which may be remotely located or positioned near the repair portion(240).

As mentioned above, the containment structure (620) preventscontaminants and particulates created during the repair process fromentering the external environment. However, entrapping the contaminantsand particulates within the containment structure (620) can pose asafety hazard to workers within the containment structure (620). Thus,to further ensure the safety of the workers, the containment structure(620) may be provided with access to a dust collection system, as seenin FIG. 6.

After the blade (100) has been repaired by installing the repair portion(240), the method concludes by removing the blade reinforcementstructure (600) from the blade (100). Of course, the method may berepeated on the wind turbine's remaining blades (100) should theyrequire any repairs.

Numerous alterations, modifications, and variations of the preferredembodiments disclosed herein will be apparent to those skilled in theart and they are all anticipated and contemplated to be within thespirit and scope of the claimed method. For example, although specificembodiments of the various apparatus associated with the method havebeen described in detail, those with skill in the art will understandthat the preceding embodiments and variations can be modified toincorporate various types of substitute and or additional or alternativematerials, relative arrangement of elements, and dimensionalconfigurations. Accordingly, even though only few variations of thevarious apparatus associated with the method are described herein, it isto be understood that the practice of such additional modifications andvariations and the equivalents thereof, are within the spirit and scopeof the method as defined in the following claims. The correspondingstructures, materials, acts, and equivalents of all means or step plusfunction elements in the claims below are intended to include anystructure, material, or acts for performing the functions in combinationwith other claimed elements as specifically claimed.

We claim:
 1. A method of repairing a wind turbine blade (100) whilemounted on a tower (500) without removing the blade (100) from the tower(500), comprising: positioning the blade (100) in a substantiallyvertical orientation; suspending a containment structure (620) from anacelle (400) via a hoisting system (1600) including at least one cableand at least one hoist, and further including the step of operating thehoist to raise the containment structure (620) to a damaged portion(230) of the blade (100); enclosing the damaged portion (230) of theblade (100) within the containment structure (620) and creating a sealabove and below the damaged portion (230) of the blade (100);controlling the temperature of the air within the containment structure(620); removing the damaged portion (230) of the blade (100); installinga repair portion (240) to the blade (100) where the damaged portion(230) was removed; and releasing the seal and operating the hoist toremove the containment structure (620) from the blade (100).
 2. Themethod of claim 1, further including the step of curing the repairportion (240) within the temperature controlled containment structure(620).
 3. The method of claim 1, wherein the containment structure (620)includes a work platform.
 4. The method of claim 3, wherein thecontainment structure (620) includes a waterproof shell.
 5. The methodof claim 3, wherein the containment structure (620) includes a HVACsystem to heat and cool the containment structure (620) and the repairportion (240) of the blade (100), and the containment structure (620)includes a dust collection system.
 6. The method of claim 1, furtherincluding the step of controlling the humidity of the air within thecontainment structure (620).
 7. The method of claim 1, further includingthe step securing a blade reinforcement structure (600) to the blade(100) to reduce stress on a portion of the blade (100), wherein at leasta portion of the blade reinforcement structure (600) is within thecontainment structure (620).
 8. The method of claim 7, wherein the stepof securing a blade reinforcement structure (600) to the blade (100)further includes the step of securing a clamping structure (700) to theblade (100) including securing a primary proximal clamp (800) and aprimary distal clamp (1000) to the blade (100), and further includes thestep of interlocking the primary proximal clamp (800) and the primarydistal clamp (1000) with a clamp interlock structure (1200), wherein thedamaged portion (230) is located between the primary proximal clamp(800) and the primary distal clamp (1000).
 9. The method of claim 8,wherein the clamp interlock structure (1200) includes at least acompressive side interlock structure (1202), and further including thestep of applying force to the primary proximal clamp (800) and theprimary distal clamp (1000) with the compressive side interlockstructure (1202) thereby reducing stress on a portion of the blade (100)located between the primary proximal clamp (800) and the primary distalclamp (1000).
 10. The method of claim 8, wherein the clamp interlockstructure (1200) includes at least a tensile side interlock structure(1204), and further including the step of applying force to the primaryproximal clamp (800) and the primary distal clamp (1000) with thetensile side interlock structure (1204) thereby reducing stress on aportion of the blade (100) located between the primary proximal clamp(800) and the primary distal clamp (1000).
 11. The method of claim 8,wherein the clamp interlock structure (1200) includes at least acompressive side interlock structure (1202) and a tensile side interlockstructure (1204), and further including the step of applying force tothe primary proximal clamp (800) and the primary distal clamp (1000)with the compressive side interlock structure (1202) and the tensileside interlock structure (1204) thereby reducing stress on a portion ofthe blade (100) located between the primary proximal clamp (800) and theprimary distal clamp (1000).
 12. The method of claim 8, furtherincluding the steps of securing a secondary proximal clamp (900) abovethe primary proximal clamp (800), securing a secondary distal clamp(1100) below the primary distal clamp (1000), interlocking the primaryproximal clamp (800) and the secondary proximal clamp (900) with asecondary proximal clamp interlock structure (1210), and interlockingthe primary distal clamp (1000) and the secondary distal clamp (1100)with a secondary distal clamp interlock structure (1220).
 13. The methodof claim 8, wherein the primary proximal clamp (800) is secured above amax chord location (180) and the primary distal clamp (1000) is securedbelow the max chord location (180).
 14. The method of claim 13, whereinthe secured primary proximal clamp (800) cannot pass the max chordlocation (180).
 15. The method of claim 8, further including the step ofsuspending the blade reinforcement structure (600) from the nacelle(400) via a reinforcement structure hoisting system including at leastone reinforcement structure cable and at least one reinforcementstructure hoist, and further including the step of operating thereinforcement structure hoist to raise the blade reinforcement structure(600) to the damaged portion (230).
 16. The method of claim 1, whereinthe step of securing the blade reinforcement structure (600) to theblade (100) further includes the step of stabilizing the blade (100)from the tower (500) by securing a load transfer structure (1300) to theblade (100) and the tower (500), wherein the load transfer structure(1300) includes an adjustable blade-to-tower support (1400) having ablade attachment device (1410), a longitudinally adjustable device(1420), and a tower attachment device (1430).
 17. The method of claim16, further including the step of applying a force to the blade (100)with the load transfer structure (1300).
 18. The method of claim 17,wherein the blade attachment device (1410) includes a blade attachmentvacuum device (1412) and the tower attachment device (1430) includes atower attachment vacuum device (1432).
 19. The method of claim 17,wherein the blade attachment device (1410) includes a primary proximalclamp (800) applying a clamping force to the blade (100).
 20. The methodof claim 17, wherein the load transfer structure (1300) is secured tothe blade (100) below the damaged portion (230).